Quote:The universe has an infinite number of particles.
That's just not true.
It's also not part of the typical argument for not having a center, I think you are just making things up now because you don't really know why there is no center, but you've heard experts say it, so you're saying it too.
Quote:There is no 'center' to the surface of a sphere either. And if dots (like points of mass) were painted on the surface of a sphere in an evenly distributed manner (as matter is distrubuted in the Universe (refer to COBE and WMAP), there would be no center to the density of the dots either.
1) According to this argument, then, no object truly has a center of mass, because the COM of any 2 points on a sphere will be inside the sphere.
2) My astronomy teacher also said that the matter was on the surface of a sphere. In fact he was quite convinced of it...
but he didn't know why.
And I hear it over and over, and there are websites that say it too -- and if it is true, then I agree that there is no center of mass. But why do people think this?
Here's one interpretation I can think of:
All matter started on the surface of a small sphere. The sphere's radius grows at a constant rate, causing all particles in the sphere to expand at an accelerating rate. But the surface of a sphere is 2 dimensional, and our space is at least 3 dimensional, so we have to introduce another dimension to the expanding spherical surface model.
However, if that is the case, then tha argument does not hold up, because the 2 dimensions that define the position on the sphere surface and the 3rd dimension that defines the sphere, can be plotted onto a standard cartesian axis and a COM can be found in conventional ways, and that point would still be on the surface of the hypersphere.
